Terminal assembly



F. A. DOTTER ER TERMINAL ASSEMBLY Filed April 8, 1955 jnveni'aftv fiambflaiierer.

Patented 3,

UNITED S ATES PATENT OFF-ICE Application April 8, 1935, Serial No.15,185

d-(Jlaims.

This invention. relatesto terminal assemblies, and more particularly isdirected to a terminal assembly for connecting a fiexible conductor orthe like to a fixed terminal or switch contact member.

In the preierred embodiment of the invention, I provide a two-pieceterminal assembly which is rigidly mounted on a suitable supportingblock,

terminal plate or the like, and which is adapted to engage andresiliently maintain the end or a conductor in fixed contactingengagement therewith. The terminal assembly comprises a rigid framemember having a receiving portion into which the end of the conductor isextended, and a resilient contacting spring member adapted to force theend of the conductor into locking engagement with the frame member andinto pressure contact with a similarly curved portion of the resilientcontacting piece.

One object of the present invention is to provide a simplified'terminalassembly formed from metal stampings or the like, which can be readilyassembled and secured in fixed position upon a terminal block orinsulating plate.

Another object of the present invention is to provide a terminalassembly in which the end of the conductor is received in firm lockingengagement within the assembly, whereby it will not be accidentallywithdrawn or removed from the terminal assembly, and at the same timewill be maintained in tight pressure contact with the contacting elementof the assembly, whereby no rattling or vibration of the conductorwithinthe terminal assembly is produced.

Another object of the present invention is to provide a terminalassembly in which the conductor may be readily inserted into theassembly and locked in position without requiring thetightening orthreading of any clamping mem-' bers or the like onto the conductormember.

A still further advantage secured by the present invention is theprovision of an assembly wherein the conductor may be readily removed,when desired, from the assembly without the necessity of unthreading theclamping engagement of threaded parts or the like, and without requiringthe use or any special kind of tools or other in-- such as t economicaland simplified construc-' tion of t e assembly, the tight lockingengagement of the conductor within the assembly, and the facility withwhich connection to and disconnection from the assembly can be made,will appear more fully from the following detailed description, which,taken'in conjunction with the accompanying drawing, will disclose tothose skilled in the art the particular construction and operation of apreferred form of the present invention.

In the drawing:

Figure 1 is a perspective view of the terminal assembly mounted upon aninsulating block;

Figure 2 is a perspective view of the bullet-type end member appliedover the end of a stranded conductor;

Figure 3 is a side elevational view showing the conductor in fixedposition within the assembly; and

Figure 4 is a front elevational view of the assembly with the conductorlocked in engagement therewith.

Referring in detail to the drawing, in Figure 1 I have provided aterminal block 5, which may be formed of an insulating material, such asfiber insulation, a molded condensation product, hard rubber or thelike, upon which is placed a resilient spring member having a baseportion 6 and an upwardly and angularly extending resilient contactingportion 1, the member 6 being preferably formed of a metal'having a highdegree of electrical conductivity, and formed by a stamping operation.

Over the base 6 of the contacting member is disposed a substantiallyrigid frame member 8, having at one end thereof a downwardly extendinglug portion 9 adapted to project into a suitable recess formed in thebase plate 5. Lug 9 also fit into a corresponding notch in base 6, asclearly shown in Figures 1 and 4. The frame member 8 at the opposite endthereof has an upstanding conductor-receiving portion l2 in the form ofa flat plate, which extends vertically upwardly from the plane of thebase 5, through a slot I3 formed in the angularly extending resillentcontact finger I. The member i2 is provided, at its upper end, with alug portion i4,

defining vertically extending shoulder i5 adapted to restrain themovement of the member I over the top of the vertical portion E2 of theframe member 8.

The members 6 and 8 are secured in fixed position on the base plate 5 bymeans of a rivet member it, which is headed over, as shown at ll, aboutthe defining edge of the opening in the frame member 8, and extendsthrough the base plate 5. The rivet It has a contact portion l8 formedon the undersurface of the base plate, which contact portion it maybeengaged by a'suitable rotating or oscillating switch contact finger, ormay be engaged by any desired contacting means for effecting electricalcontact with the conductor locked in the terminal assembly.

The portion I! of, the member 8 is also provided, adjacent its upperend, with'an opening 20 of substantially ,key-hole shape, which openinghas an enlarged cylindrical portion 22, and a corresponding cylindricalportion 23 of smaller radius extending from one side of the cylindricalportion 22 and forming a continuation of the opening at this sidethereof.

The contact portion 1 of the base member 6 is provided with arcuatelyformed offset portions 24 adjacent the opening 23 formed in the framemember l2, which arcuate portions 26 are adapted to have rotativemovement about a center disposed substantially at the bend connectingthe base portion 6 with the contact finger l. The inherent resiliency ofthe contact finger portion l provides for movement of this member fromthe full line position shown in Figure 3, in which the member i hasmoved toward the shoulder i5, which shoulder maintains it in fixedposition against its inherent resiliency, to the dotted line positionshown in Figure 3, in which position the arcuate portions 24 have beendisposed beyond the limits of the area defined by the opening 20,whereby the entire opening is available for reception of the end of aconductor. truded pin or boss 25' limits movement of the finger portionl in this direction.

Referring now in detail to Figure 2, I have shown a stranded conductor28, which is provided rearwardly of its extending end, with braidedinsulation 2?, or any other desired type of insulation, and which hasrigidly secured to its end a bullet-like terminal lug indicatedgenerally at 28, comprising an enlarged annular shoulder 29, a pair ofsubstantially similar cylindrical surfaces defining therebetween anannular groove 32 the side walls of which are radial to surfaces 30. anda tapered end portion 83 disposed forwardly of the outer cylindricalsurface 30.

The diameter of the surfaces 30 is such that they may pass through theportion 22 of the opening 20, but will not pass through the portion 23of this opening. In inserting the end of the conductor into engagementwith the terminal assembly, the finger portion l is flexed manually tothe position shown in dotted lines in Figure 3, and the tapered end 33of the terminal portion 28 of the conductor is then inserted through theportion 22 of the opening 20. The terminal portion 28 is then movedinwardly through this opening, in a direction normal to the plane ofmember 12, substantially as shown in Figure 4, until the two surfaces 39are disposed upon opposite sides of the vertically extending portion i2of the rigid frame member 8.

Upon release of the resilient finger member 'i, the arcuate portions 2 1thereof disposed on opposite sides of the slot it are adapted to engagethe corresponding arcuate surfaces of the cylindrical portions 30 of theterminal connector, and urge the connector into the position as shownclearly in Figure 3, with the annular groove 32 of the terminal engagedwithin the reduced arcuate portion 23 of the opening 223. This forcesthe peripheral surface of the groove 32 into'tight engagement with thedefining edge 23 of the opening 23, and at the same time the resiliencyof the finger 3 provides for firm pressure contact between the arcuatesurfaces 22 thereof on opposite sides of the slot l3 and thecorresponding arcuate surfaces of the cylindrical portions 30 of theterminal lug. lhis is shown in Figure 3, from which it will be notedthat the extent of portion 23 of opening at is somewhat greater than thesemicircumference of member 28 in the plane of roove 32. Withdrawal ormovement of the conductor 28 normal to the plane of the portion l2 ofthe rigid frame member is prevented by means of the abutting engagementof the shoulders, formed between the surfaces 30 and the groove Asuitable exreams 32, against the opposite surfaces of the portion i2 ofthe frame member. This therefore rigidly locks the conductor in fixedposition within the terminal assembly, and prevents its withdrawaltherefrom unless the'spring portion 7 of the base 3 is flexed away fromthe shoulder l5 a sufficient distance to allow the terminal connector 28to be moved to a. position such that the surfaces 30 may pass throughthe enlarged portion 22 of the opening 20. It will be noted, byreference to Figures 3 and 4, that the diameter of portion 23 of opening20 is equal to the diameter of terminal member 28 in the plane of groove32, and that the diameter of portions 30 of member 28 is approximatelyequal to that of portion 22 of opening 20, with but such clearance as isrequired for insertion and withdrawal of the terminal member. Further,nose 33 is of considerable length and tapers to its outer end, at whichit is of materially less diameter than member 28 in the plane of groove32, as is clearly shown in Figure 4.

In practice, block 5 may be secured to a supporting member, in a. knownmanner, as is usual, being thus effectively anchored. Member 1 provideselements of considerable width at opposite sides of portion or plate l2of the frame, as shown, and this member is normally disposed remote fromthe upper portion of opening 20 toward which upper portion it isyieldingly urged. In its normal position, member I may contact shoulderi5, being limited thereby against further upward movement and, in thisposition, being under initial tension,

In the uppermost position of member I arcuate portions 22 thereof areconsiderably below the restriction between portions 22 and 23 of opening20, as in Figure 1. In the lowermost position of member l, determined bythe stop element 25', portions 22 thereof are disposed at the lowersegment of portion 22 of opening 20. Portions 24 of member "5 are curvedon substantially the radius of portion 22 of the opening, and the uppersurfaces thereof are coincident with the lower segment of this portionof the opening, in the lowermost position of member 1. Accordingly,portions or elements 24 of member I provide, in the lowermost positionof the latter, surfaces of appreciable width constituting, in effect,continuations of the lower portion of the circumferential wall or edgeof lower portion 22 of opening 20. This will be clear from Figures 3 and4, in the former of which member 1 is shown, in dotted lines, in itslowermost position.

Since portions or elements 24 of member 5 are disposed, in the uppermostposition of the latter, considerably below the restriction betweenportions 22 and 23 of opening 20, nose element 33 of member 28 may beinserted through the opening sufficiently to dispose portion 30 ofmember 28, adjacent nose 33, in contact, for the major portion of itswidth, with the upper face of adjacent element 2d of member 1. In thusinserting member 28 the latter is conveniently grasped by shoulder orbase element 29 thereof, and no downward displacement of member '5 isnecessary. Thereafter member 7 is forced downward into its lowermostposition, by pressure exerted upon member 28, and the latter is theninserted through porwhich time member 1 acts, due to its inherentresiliency, to force member .28 into portion 23 of opening 20, where itis effectively anchored in the manner previously described. Withdrawalof member 28 may be effected by forcing member I into its lowermostposition, by downward pressure exerted on member 28, and the latter maythen be withdrawn without difllculty from opening 20, since elements 24of member 1 preclude possibility of the outer shoulder of groove 32engaging the edge of the lower segment of portion 22 of opening 20. Theterminal lug II may.thus

be inserted into and withdrawn from the terminal connector or assemblywith expedition and facility, and with the use of but one hand. This isfrequently desirable and advantageous, and provides. an alternative tothe method of insertion and withdrawal of the terminal member previouslydescribed.

It is therefore apparent that I have provideda terminal assemblyproviding for fixed and rigid pressure contact of the contacting portionof the assembly with the conductor, and for preventing.

rattlingor vibration of the conductor when engaged in the terminalassembly. Further, I have provided a construction of relatively simpleform, in which the two pieces comprising'the structure are formed frommetal stampings, and may be readily assembled by means of a single rivetmember, which rivet member in turn, provides a switch contact fordirectly connecting the terminal assembly to a suitable switch operatingmechanism or the like.

I do not intend to be limited to the exact struc ture which I have shownand described, inasmuch as certain variations in design and position ofthe parts may be provided, without, however, departing from theunderlying principles of the present invention.

Having therefore described my invention in accordancewith the patentstatutes, what I claim as new and desire to secure by Letters Patent is:

1. A terminal assembly for receiving and locking a conductor againstdisplacement, said conductor having a cylindrical portion with anannular groove intermediate the ends thereof, comprising a base, aresilient contact member having a portion lying on said base and havinga substantially planar portion extending angularly from said baseprovided with a longitudinal slot and displaceable about an axisparallel to and adjacent the base, an L-shaped frame plate having oneleg thereof superposed on the base portion of said contact member andsecured thereto.

' the other leg of said plate partiallyprojecting through said slot and"having a pair of overlapping circular apertures of different diameters,the centers of said apertures lying in the arc of movement of saidslotted portion of said contact member, whereby said member may bedisplaced to allow insertion of said conductor into the larger of saidapertures and upon release urges the grooved portion of said conductorinto the smaller of said apertures.

2. The combination with a conductor terminal having a cylindricalportion provided with an annular groove intermediate its ends defined byradial shoulders, of a terminal assembly for receiving said conductor,comprising a resilient contact member having a planar base portion andan angularly extending substantially planar named base portion andrigidly securedthereto and having a planar portion projecting partiallythrough said slot and extending normal to said contact portion, saidprojecting portion having overlapping circular apertures of diameterscorresponding to said cylindrical portion and said groove of saidconductor, said slotted portion being displaceable to provide forinsertion of said conductor into the larger of said apertures andmovable laterally by said slotted portion to engage said groove in thesmallerof said apertures with the radial shoulder engaging oppositedefining surfaces about said last named aperture whereby said conductoris held against lateral and longitudinal movement in said assembly.

3. A terminal assembly for receiving a conductor, said conductor havinga cylindrical portion with an annular groove-intermediate the endsthereof, comprising a base, a resilient contact member having a portionlying on said base and a substantially planar angularly extendingportion provided with a longitudinal slot, a frame plate having a baseportion superposed on the base portion of said contact member and havinga planar normally extending portion partially projecting through saidslot, said last-named portion being apertured to receive said conductor,

and meanssecuring said base portions to said base.

4. Receptacle means, comprising: a wall having an aperture for receivinga conductor terminal, and having also a recess formed in a marginalsurface; and a sheet metal member, havinga part fixed with respect tosaid wall, and a leg provided with 'a slot terminating short of theextremity of said leg, said slot being proportioned to receive saidwall, and said leg being constructed and arranged to move transverselywith respect to said aperture, the extremity of said leg beingengageable with at least one margin of said wall recess to limitmovement of said leg.

5. A terminal assembly for receiving a conductor having a portion with agroove therein, comprising a resilient contact member having anangularly extending portion provided with a longitudinal slot withconductor-engaging portions on opposite sides of the slot, aconductorreceiving plate disposed so as to extend only partially throughsaid slot, said plate being apertured to receive the groove of theconductor and the said conductor-engaging portions of the resilientcontact member being adapted to engage the conductor on opposite sidesof the groove and to hold the groove of the conductor engaged in theaperture of said plate and said connector being locked in said plate solong as the opposite sides of said groove engage the edge of theaperture in said plate, and means at the outer end of the latterengageable with the outer end portion of said contact member forlimiting the movement of the latter.

6. A terminal assembly for receiving a conductor, comprising a base, aresilient contact member having a portion lying against said base and asubstantially planar angularly extending portion provided with alongitudinal slot, a frame plate having a base portion secured to saidbase and having a planar normally extending portion partially projectingthrough said slot, said last named portion being apertured to receivesaid conductor, and means securing said base portions to said base.

FRANK A. DO'I'I'ERER.

